Pavement joint seal

ABSTRACT

Elongated, hollow elastomer seals particularly useful for sealing concrete pavement contraction joints or longitudinal joints and embodying an elongated, concave top wall, a substantially flat or V-shaped, elongated bottom wall, substantially flat, elongated side walls and an internal web structure consisting essentially of a longitudinally elongated, vertical web joined at its longitudinal edges with and extending between said to and bottom walls substantially midway between said side walls and a pair of longitudinally elongated, diagonal webs extending transversely diagonally downwardly from the upper portion of the vertical web to respective lower portions of said side walls.

United States Patent 1 Brown PAVEMENT JOINT SEAL [75] lnventor: Delmont D. Brown, North Balv timore,0hio

[73] Assignee: The D. S. Brown Company, Baltimore, Ohio [22] Filed: Dec. 4, 1970 [21] Appl. No.: 95,378

Related US. Application Data [63] Continuation of Ser. No. 787,108, Dec. 26, 1968,

abandoned.

[52] US. Cl. ..94/18 [51] Int. Cl. ..E0lc 11/10 [58] Field of Search ..94/18 [56] References Cited UNITED STATES PATENTS 3,276,336 10/1966 Crone ..94/18 3,395,627 8/1968 Barton ..94/18 51 Jan. 9, 1973 3,595,141 7/1971 Boney et al ..94/18 Primary Examiner-Nile C. Byers, Jr. Attorney-Johnston, Root, OKeeffe, Keil, Thompson & Shurtleff [57] ABSTRACT Elongated, hollow elastomer seals particularly useful for sealing concrete pavement contraction joints or longitudinal joints and embodying an elongated, concave top wall, a substantially flat or V-shaped, elongated bottom wall, substantially flat, elongated side walls and an internal web structure consisting essentially of a longitudinally elongated, vertical web joined at its longitudinal edges with and extending between said to and bottom walls substantially midway between said side walls and a pair of longitudinally elongated, diagonal webs extending transversely diagonally downwardly from the upper portion of the vertical web to respective lower portions of said side walls.

2 Claims, 3 Drawing Figures PATENTEDJAN 9 I925 3.709.115

I N VEN TOR. DELMONT D. BROWN PAVEMENT JOINT SEAL This application is a continuation of Ser. No. 787,108 filed Dec. 26, 1968, and now abandoned.

BACKGROUND OF INVENTION .This invention concerns seals for joints in pavements and is particularly adapted for use in contraction joints and longitudinal joints. Such joints have a relatively narrow width dimension and a relatively small amount of movement, i.e., the distance between minimum and maximum opening of the joint due to contraction and expansion of the concrete pavement. Longitudinal joints generally have even less movement than do contraction joints.

In recent years, hollow, elongated, elastomer strips have been developed for use as seals in concrete joints such as expansion and contraction joints in concrete roadways, air strips, and the like. These joint seals are inserted in a laterally compressed state into the joints to seal them against intrusion by water, solids and the like. The sides of the joint seal strips are in tight, sealing contact with the side walls of the slots or grooves forming the joint.

Joints of the aforesaid character are used in concrete pavement or similar concrete structures to permit expansion and contraction of a given length of the concrete under varying temperature conditions. Expansion joints, which extend transversely across roadways at predetermined intervals, are wide enough to accommodate the lineal expansion of a pavement under warmer climate conditions. Transverse contraction joints control random cracking by creating transverse lines of weakness and are usually formed by a spacer member which is inserted between adjacent pavement sections before or after the concrete it poured, or by sawing a groove across a continuous strip of pavement, usually after the concrete has taken its initial set.

Expansion joints are formed crosswise of a pavement or highway the full depth of the slab for compensating for expansion of longitudinally extending pavement sections. Contraction joints are usually about onefourth the depth of the slab. Longitudinal joints are formed between longitudinal strips of pavement, for example, of a two or more lane highway. The major function of longitudinal seals is to prevent foreign material from entering the joints between the side-by-side longitudinal strips or lanes of pavement.

It is desirable that all such joints be sealed in order to prevent accumulation of unwanted particles such as sand, gravel, or other incompressibles from entering the open joint, filling the joint and thereby preventing the joint from closing upon expansion of the concrete in warm weatherv Joints are also sealed to preventinftltration of water, the freezing of which in cold weather canbe responsible for heaving and cracking of the pavement or damage to the joint. In warm weather, water entering the joint can be responsible for washing away and erosion ofthe subgrade.

It has been standard practice for many years to fill such joints with an asphalt or similar type of caulking filler which would yield during warm weather when the width of the joint becomes smaller due to expansion of the adjacent pavement lengths. Joints having such filling materials must be repaired and replaced periodically and normally require inspection and repairs at 6 month intervals. Caulking type fillers have several other disadvantages, a major one of which is that appreciable amounts thereon are squeezed out of the joints in warm weather when the joints are most closed and the sealing of the joints is lost when they open in colder weather.

Contraction joint and longitudinal joint seals heretofore known include elongated, elastomer seals having longitudinally elongated top, bottom and side walls of the general arrangement herein described. One type of prior joint seal is described and illustrated in U.S. Pat. No. 3,179,026, wherein the internal truss structure embodies a lower set of diagonal webs extending between side walls in an X-arrangement and an upper set of diagonal webs extending from the midpoint of the V' shaped upper wall diagonally outwardly to the side walls. Such known elastomer seals are useful for the sealing of contraction joints and may also be used for the sealing of longitudinal joints. Another type of known internal web structure for contraction joint seals embodies two webs, one of which is a vertical web extending approximately medially between the side walls from the top wall to the bottom wall and the other of which is a horizontal web or shallow V-web extending between the side walls and intersecting the vertical web. These webs form an internal structure having the general shape of a cross. Still another type has an internal web structure consisting of a pair of downwardly diverging diagonal webs extending respectively from the longitudinal mid-portion of a V-shaped top wall to the lower edges of the side walls. Elongated elastomer seals heretofore known, useful in sealing joints having more movement than contraction or longitudinal joints, e.g., expansion joints and bridge joints, include seals of the type illustrated in U.S. Pat. Nos. 3,358,568 and 3,276,336.

BRIEF DESCRIPTION OF THE INVENTION Briefly, the present invention concerns joint seals of the type particularly useful in the sealing of contraction and longitudinal joints in concrete pavementv The subject seals are characterized by a minimum of webs forming the internal web structure without serious sacrifice to the lateral, outward thrust of the side walls of the seals against the side walls of the joint when the seal is in a laterally collapsed state. It is important that such lateral thrust be maintained throughout the entire range of movement of the joint to maintain the sealing of the joint against intrusion of water, ice or snow and dirt or other incompressible solids. The most critical period for maintaining such sealing of the joints is the period from late fall through early spring, at which time the joints have opened to the greatest degree. Intrusion of water into the joint during such time in a warm or thawing spell followed by freezing of the intruded water and subsequent expansion thereof can adversely affect the joint by the expansion pressures created. The intrusion of dirt or other incompressible solids into the joint can ultimately result in a packing of the joint with incompressible solids which then preclude joint movement as the joint begins to close during the period of later spring through early fall. If the joint is unable to move, the pavement sections may become sufficiently stressed so as to cause heaving or random cracking of the pavement slabs.

The subject elongated, hollow elastomer seals have longitudinally elongated top, bottom and side walls defining a hollow, tubular-like elastomer member adapted to be laterally compressed and inserted in the laterally compressed state into joints of the character above described. The lateral or outward thrust of the side walls of the seal against the side walls of the joint is increased by an elastomer internal web structure functioning in coaction with the top, bottom and side walls to provide lines of increased localized thrust along the upper and lower edges of the side walls against the side walls of the joint. The internal web structure of the subject'seals consists essentially of a longitudinally elongated, vertical web joined at its longitudinally edges with and extending between the top and bottom walls substantially midway between the side wallsand a pair of longitudinally elongated, diagonal webs extending transversely diagonally downwardly from the upper portion of the vertical web to the respective lower portions of said walls. The bottom wall is a substantially flat or V-shaped wall. The lower, longitudinal edge of the vertical web is joined with the V-shaped bottom wall at the apex of the V or the longitudinal mid-line of the flat bottom wall. Upon lateral collapse of the seal in a joint, the apex of the V or said mid-line moves downwardly and pulls the vertical wall and (through the latter wall) the longitudinal midportion of the top wall downwardly with the result that the top wall collapses inwardly into a concave configuration, preferably substantially a V shape.

The top wall of the seals herein may be substantially flat or more preferably has a shallow V configuration along the longitudinal midportion thereof. If desired, the entire top wall may have a shallow V configuration. Furthermore for purposes of effecting a better seal of the upper. longitudinal edges of the side walls with the side walls of the joint, these upper longitudinal edges may have a small, laterally projecting, preferably substantially sharp-edged lip, each of which provides a relatively sharp, longitudinal line of localized lateral thrust against the side walls of the joint along the respective upper corners of the seal. The subject seals have, among others, the advantage of capability of being laterally compressed for insertion into pavement joints without tendency to twist. Therefore, the respective upper longitudinal edges remain even when the seal is laterally collapsed.

DESCRIPTION OF THE DRAWING A preferred embodiment of the invention is illustrated in .the drawing wherein:

FIG. I is a perspective view of a fragmentary end segment ol'the embodiment;

FIG. 2 is a vertical section through a contraction joint in concrete pavement (shown in fragment) with the sealing strip embodiment of FIG. I mounted therein in a laterally collapsed state; and

FIG. 3 is a fragmentary perspective view of the illus trated seal with an alternate shape of the bottom wall.

DESCRIPTION OF PREFERRED EMBODIMENTS Referring to the drawing, the elongated, hollow elastomer seal comprises side walls 11 and 12 which are preferably substantially parallel, elongated, elastomer walls. The upper longitudinal edges of the side walls are connected by an elongated elastomer top wall 13. The latter wall comprises substantially flat or planar, outer wall segments or strips 14 and 15 and a shallow V-shaped midwall portion 16 which extends longitudinally of the midportion of upper wall 13. The upper wall [3 preferably is substantially symmetric as viewed in end elevation or transverse cross section and has its apex 17 extending substantially longitudinally midway of the upper wall 13.

The bottom wall 20 may be a substantially V-shaped wall and comprises transversely diagonal wall segments 21 and 22. The V-shaped bottom wall 20 preferably also is substantially symmetric and has its apex 19 substantially directly below the apex 17. As shown in FIG. 3, the bottom wall 20a may also be a substantially flat or planar wall when the seal is uncollapsed. Upon lateral collapse of the seal, the bottom wall becomes V- shaped or U-shaped.

The internal web structure of the seal consists essentially of the vertical web 25 and the diagonal webs 23 and 24. The vertical web 25 is joined at its upper longitudinal edge with the apex 17 of the top wall 13 and at its bottom longitudinal edge with the apex 19 of the bottom wall 20. As can be seen by comparing FIGS. 1 and 2, the V-shaped bottom wall elongates when the seal I0 is laterally collapsed. This vertical elongation of the bottom wall draws the web 25 downwardly and by virtue of its connection to the longitudinal midportion of top wall 13, the top wall is pulled downwardly into the general configuration ofa V as shown in FIG. 2. It is desirable that the top wall 13 collapse inwardly so that none of the top wall projects above the pavement surface, where it could be struck by. tires passing over the joint. Continual striking of the sealing strips by tires tends to work the seal out of the joint.

The diagonal webs 23 and 24 are longitudinally elongated, diagonal webs respectively extending transversely diagonally downwardly from the upper portion of the longitudinally elongated vertical web 25 to respective lower portions of the side walls. The resultant internal web structure collapses substantially as shown in FIG. 2 when the seal is laterally collapsed. The diagonal webs 23 and 24 bend or fold into longitudinal bends or folds not substantially exceeding about 90. Bends or folds approaching I are undesirable because such bends or folds place high amounts of stress in the web truss structure, particularly at hot temperatures in the order of l20-l40F. The latter temperatures are relatively common in pavements during the hot summer months. At such temperatures, the joints. are in their most closed state and the seal is in its most laterally collapsed state.

The longitudinally bent or folded elastomer webs 23 and 24, by virtue of their elastic properties, seek their original, substantially planar shape as shown in FIG. I. In so doing, these diagonal webs exert at their'lower longitudinal edges lateral thrust against the respective lower portions of the side walls 11 and 12 and thus create localized lines of thrust force along the lower longitudinal edges of the side walls against the side walls 27 and 28 of the joint 29. The joint 29 is in FIG. 2 a contraction joint, the crack 30 therebeneath being a plane of weakness crack as aforedescribed.

The elastomer, substantially V-shaped top and bottom walls 13 and 20,in the laterally collapsed state of the strip 10, also seek by virtue of their elastic proper ties their original shape as shown in FIG. 1. An upward thrust vector is imparted to the vertical web 25 by the longitudinally bent or folded diagonal webs 23 and 24. The upward thrust on the vertical web 25 coacts with the force ofelastic recovery in the concavely collapsed top wall 13 to augment the thrust force of the seal against the side walls 27 and 28 along localized longitudinal lines of thrust at the upper longitudinal edges of the side walls 11 and 12. For purposes of effecting a better seal between said upper longitudinal edges and the side walls of the joint, the sealing strip may be provided at said upper longitudinal edges with outwardly projecting ribs 31 and 32. These ribs preferably have a substantially sharp edge 33 whereby the primary line of thrust force along the upper longitudinal edges of the side walls is concentrated at the sharp edges.

The lower longitudinal edges of the diagonal webs 23 and 24 preferably are joined with the lower portions of the respective side walls 11 and 12 substantially along the lower longitudinal edges thereof, i.e., substantially at the longitudinal lines of juncture 35 and 36 of the side walls with the bottom wall. The upper longitudinal edges of diagonal webs 23 and 24 may be joined with the upper portion of vertical web 25 along the upper longitudinal edge of the latter, i.e., substantially at the longitudinal line ofjuncture of the vertical web 25 and the apex 17 of top wall 13, but more preferably, these webs are joined at a longitudinal line of juncture 34 which is slightly below the apex 17.

The joinder of the lower longitudinal edges of said diagonal webs substantially at junctures 35 and 36 is preferred because, with such arrangement, the elastic recovery forces in respective pairs of diagonal webs and bottom wall segments 21, 23 and 22,24 coact to exert lateral thrust forces along localized lines of thrust at longitudinal lines ofjuncture 35 and 36, respectively. Thus, the seals herein have primary, longitudinal lines ofsealing thrust against side walls 27 and 28 of the joint 29 along the upper longitudinal edges of side walls 11 and 12. They have secondary longitudinal lines of sealing thrust at lines ofjuncture 35 and 36 alongthe lower longitudinal edges of said side walls. The latter lines of thrust are also advantageous for holding the seal in place in the event the upper lines of thrust should be disturbed temporarily, e.g., by downward distortion of the top wall ofthe seal by automotive tires striking dirt, stones, snow or ice accumulated on the top wall of the seal. The substantially flat or planar shape of the bottom wall (FIG. 3) or a shallow V-shape is preferred where maximum thrust effect, transmitted via the vertical web 25 from the bottom wall to the top wall as aforedescribed, is desired.

in any of the forms of the invention herein, the seals should be made of good quality elastomer formulations in order that these seals retain their elastic properties with aging under environmental conditions. To this end, the elastomer composition should be an elastomer formulation which is extrudable, and which, upon vulcanization, will be resistant to deterioration and/or loss of resilience after exposure to hot and cold weather conditions, sunlight, and like elements of nature in the use thereof in joints of pavement, air strips, and the like. Care should be exercised in selecting an elastomer formulation whereby the seal will retain its flexibility and elastic recovery force generation at the coldest temperatures to be encountered in the field. The

presently best-known elastomer is neoprene, particularly the crystal]ization-resistant types thereof.

It is thought that the invention and its numerous attendant advantages will be fully understood from the foregoing description, and it is obvious that numerous changes may be made in the form, construction and arrangement of the several parts without departing from the spirit or scope of the invention, or sacrificing any of its attendant advantages, the forms herein disclosed being preferred embodiments for the purpose of illustrating the invention.

I claim 1, An elongated, hollow seal useful for sealing concrete pavement contraction joints which comprises elongated top, side and bottom elastomer walls forming an elongated, hollow, elastomer sealing strip, said side walls being substantially planar, said top wall being substantially symmetrically, transversely concave and consisting of substantially horizontal outer segments connected by a shallow, V-shaped longitudinal midportion, said bottom wall being V-shaped and joined to the lower edges ofsaid side walls, and an elastomer internal web structure comprising a pair of longitudinally elongated, diagonal webs extending transversely diagonally and symmetrically downwardly from the upper midportion of said upper wall to respective lower edges of said side walls, said diagonal webs being connected in said seal only at their. respective longitudinal edges to said upper midportion and to said respective lower edges of said side walls, and a vertical web joined at its longitudinal edges with said V-shaped longitudinal midportion of said top wall and the apex of the V of said bottom wall and extending substantially midway between said side walls.

2. An elongated, hollow, elastomer seal useful for sealing concrete pavement contraction joints which comprises elongated top, side and bottom elastomer walls forming an elongated, hollow, elastomer sealing strip, said side walls being substantially planar, said top wall being substantially symmetrically, transversely concave and consisting of substantially horizontal outer segments connected by a shallow, V-shaped longitudinal midportion, said bottom wall being V-shaped and joined to the lower edges of said side walls, an elastomer internal web structure comprising a pair of longitudinally elongated, diagonal webs extending transversely diagonally and symmetrically downwardly from the upper midportion of said upper wall to respective lower edges of said side walls, said diagonal webs being connected in said seal only at their respective longitudinal edges to said upper midportion and to said respective lower edges of said side walls, a vertical web joined at its longitudinal edges with said V-shaped longitudinal midportion of said topwall and the apex of the V of said bottom wall and extending substantially midway between said side walls, and the upper longitudinal edges of said diagonal webs intersecting said vertical web immediately below the apex of the V-shaped longitudinal midportion of said top wall. 

1. An elongated, hollow seal useful for sealing concrete pavement contraction joints which comprises elongated top, side and bottom elastomer walls forming an elongated, hollow, elastomer sealing strip, said side walls being substantially planar, said top wall being substantially symmetrically, transversely concave and consisting of substantially horizontal outer segments connected by a shallow, V-shaped longitudinal midportion, said bottom wall being V-shaped and joined to the lower edges of said side walls, and an elastomer internal web structure comprising a pair of longitudinally elongated, diagonal webs extending transversely diagonally and symmetrically downwardly from the upper midportion of said upper wall to respective lower edges of said side walls, said diagonal webs being connected in said seal only at their respective longitudinal edges to said upper midportion and to said respective lower edges of said side walls, and a vertical web joined at its longitudinal edges with said V-shaped longitudinal midportion of said top wall and the apex of the V of said bottom wall and extending substantialLy midway between said side walls.
 2. An elongated, hollow, elastomer seal useful for sealing concrete pavement contraction joints which comprises elongated top, side and bottom elastomer walls forming an elongated, hollow, elastomer sealing strip, said side walls being substantially planar, said top wall being substantially symmetrically, transversely concave and consisting of substantially horizontal outer segments connected by a shallow, V-shaped longitudinal midportion, said bottom wall being V-shaped and joined to the lower edges of said side walls, an elastomer internal web structure comprising a pair of longitudinally elongated, diagonal webs extending transversely diagonally and symmetrically downwardly from the upper midportion of said upper wall to respective lower edges of said side walls, said diagonal webs being connected in said seal only at their respective longitudinal edges to said upper midportion and to said respective lower edges of said side walls, a vertical web joined at its longitudinal edges with said V-shaped longitudinal midportion of said top wall and the apex of the V of said bottom wall and extending substantially midway between said side walls, and the upper longitudinal edges of said diagonal webs intersecting said vertical web immediately below the apex of the V-shaped longitudinal midportion of said top wall. 